Correct answer: A

The correct answer is $4$ adult and $3$ student tickets.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Use $a+s=7$ and $10a+6s=58$. Substitution gives $a=4$ and $s=3$.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.

Correct answer: B

The correct answer is $4$ rabbits.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Let $r+c=10$ and $4r+2c=28$. Substitution gives $r=4$.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.

Correct answer: C

The correct answer is $3$ notebooks.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Use $p+n=8$ and $2p+5n=25$. The solution is $p=5$ pens and $n=3$ notebooks.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.

Correct answer: D

The correct answer is $6$ quarters.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Use $q+d=12$ and $0.25q+0.10d=2.10$. The solution is $q=6$ and $d=6$.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.

Correct answer: A

The correct answer is $3$ hours.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Use $w+b=6$ and $3w+8b=33$. Solving gives $b=3$ and $w=3$.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.

Correct answer: B

The correct answer is $11$ feet by $6$ feet.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Use $l=w+5$ and $2l+2w=34$. The solution is $w=6$ and $l=11$.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.

Correct answer: C

The correct answer is $4$ adult tickets.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Use $a+s=9$ and $12a+7s=83$. Substitution gives $a=4$ and $s=5$.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.

Correct answer: D

The correct answer is $500$ messages.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Set the costs equal: $20+0.05m=35+0.02m$. Then $0.03m=15$, so $m=500$.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.

Correct answer: A

The correct answer is $11$ and $7$.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Use $x+y=18$ and $x-y=4$. Adding gives $2x=22$, so the numbers are 11 and 7.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.

Correct answer: B

The correct answer is $6$ pounds.

1. Choose a system method: Use substitution, elimination, a graph, or an equivalent form that makes one variable easy to determine.
2. Solve for the ordered pair: Use $a+o=10$ and $2a+3o=24$. Substitution gives $a=6$ and $o=4$.
3. Check both equations: Substitute the ordered pair into both original equations and verify that it satisfies each one.